Zoo testing DNA of mystery apes

Scientists hope DNA analysis will reveal the origins of large, mysterious apes discovered in the heart of Africa by an Atlanta primatologist.

Genetics research has begun at Omaha's Henry Doorly Zoo on faecal samples collected this year from the rare apes to determine if they make up a new species, a new subspecies or some form of hybrid - possibly a mix between a chimpanzee and a gorilla.

"It's a new, mystery ape and we are doing the DNA fingerprinting to find out more," said Dr Lee Simmons, zoo director.

The apes, which stand up to 1.8 metres tall and have feet nearly 36 centimetres long, were first documented last year by primatologist Shelly Williams in a forest in the northern part of the Democratic Republic of Congo.

They have bodies similar to those of gorillas, but generally the facial characteristics of a chimpanzee. Williams said the animals sleep on the ground at night like gorillas, but eat a fruit-rich diet like chimpanzees.

"I can't speculate yet as to what they are. Their behaviour is so unusual. It's a puzzle. ... I feel like Dr Doolittle in the land of Oz," said Williams, who has captured some video of the animals but no photographs.

Because of their size and elusiveness, the apes have no predators - not even poachers hunt them, Williams said. With no fear of lions, leopards or hyenas, the large animals hoot at the moon as it rises and sets, which is extremely unusual for apes, she said.

"The people are afraid of them. They call them 'lion killers' because they are huge creatures," Williams said. "The folklore is they could kill lions."

Williams collected faecal samples from the animals' nests before returning in June from her most recent trip to the Congo. In August, she delivered those samples to the Omaha zoo, where they are being compared with the DNA of captive gorillas, bonobos (pygmy chimps), and chimps, said Ed Louis, a conservation geneticist leading the research at the Omaha zoo.

"If this ends up being a new species of ape, that would be amazing. Even if it's a hybridisation, that would be fascinating," Louis said. "However, at this point we don't even know what we're dealing with."

Biologically, it is possible for a chimpanzee and a gorilla to have viable, fertile offspring, Williams said.

The DNA analysis is expected to take months. However, it may be impossible to determine the apes' entire ancestry without getting a sample of blood or tissue.

Louis plans to join Williams on her next trip to the Congo, likely in November, to collect more specimens for DNA analysis.

"Without getting your hands on the animal, it's difficult to say what it is," said Louis, who in recent years has identified several new species of monkey-like lemurs in Madagascar through his genetic research.

Williams did collect hair from the apes' nests, but none of the samples included follicles, which are needed for extracting cells for DNA research. She also made molds of the apes' large footprints found in mud near the nests. The footprints were nearly five centimetres larger than the average length of a gorilla's foot, which is about 30 centimetres long.

According to Williams, what makes the gorilla-like apes even more unusual is that the closest gorillas documented in that part of Africa are thousands of kilometres away.

"The possibility is there that this is a new species due to isolation," she said.

The last discovery of a great ape was in 1902 when mountain gorillas were found in the Virunga Volcanoes, where the borders of the Democratic Republic of Congo, Rwanda and Uganda meet.

Russell Mittermeier, president of Conservation International, a Washington-based organisation that focuses on biodiversity conservation, has assisted in the discovery of six new species of monkeys and marmosets in the Brazilian Amazon. He is not ruling out the possibility that the apes Williams is studying make up a new species.

"If this turns out to be a new species of ape, it would be one of the big discoveries of primatology," he said.